Structural, spectroscopic and theoretical studies of 6-hydroxyquinolinium bromide monohydrate

Abstract

Molecular structure and properties of 6-hydroxyquinolinium bromide monohydrate have been characterized by X-ray diffraction, B3LYP/6-311++G(d,p) calculations and FTIR spectroscopy. Centrosymmetric cyclamers R44(8) of OH⋯Br− bonding two molecules of water and two bromide anions mediate the aggregation of 6-hydroxyquinolinium cations into ribbons. In the absorption spectrum, the 3250–2500 cm−1 region has been attributed to ν⋯O(w), νNH⋯Br- and νBr-⋯HO(w) vibrations. The N⋯Br, O(6)⋯O(w) and O(w)⋯Br distances, of 3.289(2), 2.647(2) and 3.343(2) Å, respectively, have been reproduced in the theoretically optimized models. The experimental and computed spectra of mono- and dihydrates are consistent in the fingerprint region. The potential energy distributions (PED) have been used to assigned bands in the vibrational spectrum.